The understanding of how motor proteins facilitate a wide array of transport-dependent cellular processes, such as chromosome segregations during mitosis and meiosis, and how these transport events are coordinated within the parameters of plant and animal development, are areas of intense interest to both cell and developmental biologists. Microtubule motors transport cellular products along microtubules (MT) in an ATP-dependent manner; the "heads" of the proteins "walk" along MT, whereas the "tails" tether the intracellular cargo. Defects in the motor protein itself, or its interacting cellular proteins results in variety of diseases, such as Charcot-Marie-Tooth type 2A and Alzheimer's. Toxins and viral particles are also transported along motor proteins. Moreover, research in a diverse set of motor proteins has led to greater insights into general transport processes of mammalian cells. The long-term goal of the proposed project is to understand the roles of the MT motor protein kinesin in cell division. The plant Arabidopsis thaliana is being used as a model system because the large number of kinesins in its genome allows for greater complexity in potential kinesin functions. After a genome-wide screen for cell division and development mutants, three kinesins were chosen for molecular characterization. Kinesins will be studied by characterizing kinesin mutations, examining kinesin spatio-temporal expression, accumulation profiles, subcellular localization during the cell cycle, and gain-of-function over-expression phenotypes.